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DRIFT ICE AND CURRENTS 



NORTH ATLANTIC 



WITH A CHART SHOWING THE OBSERVED POSITIONS OF THE ICE 
AT VARIOUS TIMES. 



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W. C. REDFIELD. 



EXTRACTED FROM THE AMERICAN JOURNAL OF SCIENCE, VOL. XLVIII. 



NEW HAVEN: 

PniNTEl) HY li. L. HAMLEN. 

1845. 



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DRIFT ICE AND CURRENTS 



NORTH ATLANTIC* 



Of the various dangers which beset the path of the mariner, 
perhaps there are none which excite to more vigilance than the 
known or expected proximity of ice. In some frequented por- 
tions of the Atlantic Ocean the ice appears almost every year, in 
the various forms of field ice, floes and massive ice-islands, drift- 
ed from the arctic regions by the constant action of the polar cur- 
rents. These ice-bearing currents, in flowing towards the south, 
must necessarily incline towards the western limits of the ocean, 
owing to the increased velocity of the diurnal rotation of ,the 
earth's surface as we depart from the poles ; a law well under- 
stood as regards the currents of air which form the trade winds. 
Hence it is that on and near the Banks of Newfoundland these 
ice-currents are found to cross the usual track of vessels bound 
from the ports of Europe to northern America. 

The quantity of ice which appears on this route of navigation 
in different years, is exceedingly various. It is sometimes seen 
as early in the year as January, and seldom later than the month 
of August. From March to July is its most common season. It 
is found most frequently to the west of longitude 44°, and to the 
eastward of longitude 52° ; but icebergs are sometimes met with 
as far eastward as longitude 40°, and in some rare cases, even 
still further towards Europe. 

Experience has shown that the proximity of ice is far less 
hazardous than rocks and shoals ; and this floating danger would 
be still less formidable were it not for the fogs and mists which it 
often causes. The thermometer has been often held up as aff"ord- 
ing sure indications of an approach to ice, by the reduction of 
temperature shown both in the air and water, and these indica- 
tions are important and should by no means be neglected. But 
there may be many cases of approach to ice where a reliance 
upon the thermometer alone could not afford security. 

On the ice chart, which is annexed, we have indicated numer- 
ous positions in which ice has been seen and reported on the 

* From the forthcoming " Memoir" of Messrs. E. & G. W. Blunt on the Dan- 
gers and Ice of the North Atlantic Ocean. 

I 



L 



4 Drift Ice and Currents of the North Atlantic. 

common route of navigation, chiefly since 1832. This will serve 
to show the region where it is most often encountered. 

Although little or no ice be seen in one passage, or even in 
many times crossing the Atlantic, yet it has been frequently met 
in such quantities as seemed to indicate a vast, or indefinite ex- 
tension of the ice-fields, towards the polar seas. And from the 
inexhaustibility of the sources of supply, and the permanent 
character of the polar currents, we may infer that there is no 
spot of ocean within the influence of these currents which has 
not, at some time, been covered with ice. 

A recital of the various authorities and marine reports from 
which our ice-chart has been compiled, might prove more tedious 
than useful. The following, however, selected from many others, 
may serve as examples of the cases in which the ice has been 
noticed by navigators. 

Ship Eli Whitney, Harding, April 7, 1836, sea account : wind 
S. S. W. and thick fog ; ordered the temperature of the water to 
be tried every half hour ; at 6 p. m. water 36*^ ; passed a small 
ice-island ; ship going west all night three knots ; 6 a. m, water 
34°, at 8 A. M. water 31^*^, passed considerable quantities of ice. 
At 10 A. M. saw a large field of ice ahead, which extended to 
the north and south as far as the eye could reach ; entered it in 
expectation of finding an opening to westward. After proceed- 
ing a cable's length, wore round and stood out as we went in, 
and then hauled the ship on the wind to the S. E. Longitude 
by account, 47° OG' W., latitude by account, 44° AV N. — April 

8, wind S. S. W., stood to the S. E. till 5 a. m. ; water 46°; 
tacked ship to the westward. At noon water 44°, latitude by 
observation, 44° 35', longitude by chronometer, 46° 56'. — April 

9, wind S. S. W. and foggy. At 4 p. m. water 34° ; wore ship 
to the S. E. At midnight water 44° ; tacked ship to the west- 
ward. At 8 A. M. wind shifted N. W. and cleared off" the fog ; 
three large islands of ice in sight ; water 44° ; latitude by ob- 
servation, 44° 17' N., longitude by chronometer, 47° 50' W. — 
April 10, wind N. W. ; passed six large islands ; water in vicin- 
ity of the ice 40°, latitude by observation, 43° 09', longitude by 
chronometer, 48° 55'. — April 11, passed four large islands of ice 
this day ; at 8 a. m. sounded and found bottom with 42 fathoms ; 
water 35° ; latitude at noon by observation, 43° ; longitude by 
chronometer, 50° 36' W. 



Drift Ice and Currents of the North Atlantic. 5 

Ship Samuel Wright, Allen, March 18, 1S3-. Latitude 43^, 
longitude 48° 43'. At 3 p. m. very foggy, came nearly in con- 
tact with a very large island of ice, about 150 feet high and one 
mile in length ; the weather extremely cold, kept the ship under 
easy sail. At 5 p. m. fell in with an English brig, and were in- 
formed we were standing for more ice, and that she had been for 
five days surrounded with it, extending from latitude 45*^ to 43°, 
and found no opening to the westward. Kept company during 
the night, and fell in. with more ice ; in the morning no ice in 
sight. 

Ship Fama, Winsor, March 183-, ,in latitude 44° 30', longitude 
48°, fell in with an immense field of ice ; tacked ship to the east- 
ward and stood off and on two days. Wind changed to N. E., 
and run 45 miles S. W. and passed the point of ice in latitude 
43° 25', longiiude 48° 50'. 

The British Tar, Hanby, left the Gulf of St. Lawrence 29th 
June, and passed through the Straits of Belle Isle. On the 3d 
of July, about 15 miles eastward of Belle Isle, found the passage 
quite blocked up with very heavy fields of ice, which obliged us 
to put back to an anchorage. On the 6th again made the ice, 
and found it more open : passed through about seventy miles of 
it. On the eastern edge, fell in with nine brigs, a ship, and a 
barque, standing ofi" and on, waiting for a passage into the straits. 
The icebergs were very numerous and immensely large, as far to 
the eastward as longitude 48°. 

Ship Oneida, Funk, May 4th, 1841, latitude 43° 40', longi- 
tude 50°, passed a number of large icebergs ; saw ice as far 
west as longitude 53°. 

The brig Anne, of Poole, William Dayment, master, sailed 
from Greenspond, Newfoundland, [N. E. coast,] 19th of January, 
1821, and in the evening encountered several floating islands of 
ice. On the following morning, at sunrise, the ship was so com- 
pletely enveloped in ice that there appeared no means of escape, 
even from the tops of the masts. The ice, in its whole extent, 
rose about fourteen feet above the surface of the water ; it drifted 
towards the southeast, and bore the ship along with it twenty 
nine successive days. On the 17th of February, Capt. D. being 
three hundred miles east of Cape Race,* in latitude 44° 37' 

* That this position was ascertained by chronometer appears doubtful. 



6 Drift Ice and Currents of the North Atlantic, 

north, perceived an opening to the southeast, and succeeded in 
disengaging himself. From the 29th of January to the 3d of 
February, the brig only made four miles a day ; and during the 
twenty nine days this navigation lasted, he descried near one 
hundred very extensive mountains of compact ice. 

Ship Isabella, Meredith, struck an iceberg on 9th May, 1841, 
in latitude 42° 2', longitude 43° 45'. The iceberg broke through 
the bows, and caused the ship to fill with water so fast that the 
crew had barely time to take to the boats, without water, provi- 
sions or clothing : the ship immediately went down, or disap- 
peared in the fog. The crew continued in the boat until the 
afternoon of the 11th, when they were picked up by the Kings- 
ton, of Hull, bound to Pictou. 

Ship Lowell, on the 10th of March, 1842, at 9 a. m., latitude 
44° 15', longitude 48° 30', came in contact with a field of ice ; 
was at that time steering W. N. W., with the wind. Tacked 
and stood to the eastward two hours, when she again tacked to 
the westward. At 2 a. m. again fell in with the ice. Continued 
beating to the southward, and falling in with the ice on the west 
tack till March 13th. Passed the southern extremity of the field 
in latitude 42°, longitude 49° 15', having seen it extending in a 
N. N. E. and S. S. W. direction, nearly 150 miles. 

A letter from Capt. Hosken, of the steamship Great Western, 
says : " April 18th, 1841, the ship steering west, at 6 p. m,, first 
saw one iceberg on the starboard bow, at 7 30 passed it ; at that 
time four or five others in sight ; at 9 15 p. m. passed several 
small pieces of ice — slowed the engines. In a few minutes after, 
the ship was surrounded with light field ice, which appeared 
similar to a field I ran through on the 11th of February, 1839. 
This induced me to go slowly, with the hope of getting through, 
as I had done on that occasion ; but by 9 30 finding it closely 
packed, and much thicker, prudence dictated our escape by the 
same channel we had entered. I then stopped and attempted to 
get the ship's head to the eastward, by turning ahead and astern 
until there was room for her to come round ; in the course of this 
operation the ship had occasionally (at least) two streaks heel 
given by either v/heel passing over large masses of ice. At 
10 15, succeeded in getting the ship's head to the eastward, and 
by 11 p. M. entirely clear. From that time went slowly, passing 
several icebergs j the night at times very clear, the aurora bo- 



Drift Ice and Currents of the North Atlantic. 7 

realis very bright. At 3 30 a. m. of the 19th, again got embayed 
in the ice ; stopped, hauled short round on our keel, and steered 
out E. by S., coasting the ice for five or six miles. At 4 20 
kept her to the westward, running through innumerable icebergs 
until 8 30, when we passed the last iceberg and field of ice." 

'' When the sun arose the ice was visible as far as the eye 
could reach, in an unbroken line from N. E. by E., by the north- 
ward to N. W. by W. ; at the same time, icebergs innumerable 
in every direction, forming one of the most magnificent sights I 
ever beheld." 

" The first iceberg we saw was ip latitude 43°, longitude 48° 
30' ; and the last in latitude 42° 20', longitude 50°. I am quite 
sure there was an unbroken field of that extent ; and from what 
I heard from Capt. Bailey, of the packet ship South America, I 
have no doubt the field ice extended, with very little break, to 
latitude 40° 30', where Capt. B. fell in with it on the morning 
of the 18th. Several other ships also fell in with it in the same 
longitude, and were completely stopped, giving them an oppor- 
tunity of killing seals, which were on it in great numbers. Some 
of the icebergs I estimate at little, if at all less than a mile long, 
and from one hundred and fifty to two hundred feet high. This 
field of ice was in large masses, some of them not less than 
twenty feet square by six feet thick or more." 

" The temperature of the water, when within two miles of 
the first iceberg seen, fell suddenly from 50° to 36° ; air 40° to 
36°. When in the ice, the water was 25°, air 28° ; during the 
remainder of the night and following morning the water was not 
higher than 30° nor the air higher than 32°. Immediately after 
passing the last ice the water became 36° and the air 42°." 

Brig Cynosure, on the 23d, 24th, and 25th of July, 1842, lati- 
tude 42°, longitude 49° 30', saw large icebergs, and was two 
days among the ice. Saw an island of ice that was estimated 
to be two hundred feet above the water, and saw several other 
islands in longitude 54°. 

Ship England, Bartlett, April, 1842, latitude 41° 29', longi- 
tude 49°, saw a large number of icebergs. 

Brig Byron, Pierson, April, 1842, latitude 41° 18', longitude 
50°, saw four large islands of ice, one about 200 feet high and 
three miles long. Saw it 30 miles off. 



8 Drift Ice and Currents of the North Atlantic. 

British brig Peace, Robson, May 9th, 1844, made the ice in 
latitude 46° 52', longitude 46° 30', being bound to the Gulf of 
St. Lawrence, and was soon so completely imbedded in a large 
field of fragments that escape was impossible. She remained 
fast until the 13th, without injury, when in the night a gale of 
wind set in, crowding the large cakes down fast upon the sides 
and bulwarks of the v^essel, which, from being in ballast, was 
soon stove in by the immense weight. On the 14th the small 
boats were got out and stocked with provisions, &c., and in the 
night of the same day the brig was abandoned. Captain R. 
with crew and boats remained upon the ice until the 18th, being 
unable to get into clear water, and on that day were taken off, in 
latitude 46° 50', longitude 45° 42', by the ship Copernicus, after 
much suffering. 

Ship Burgundy, Wotton, in May, 1844, from the latitude 45° 
30', longitude 45°, to latitude 43° 30', longitude 48°, was com- 
pletely surrounded by icebergs and drift ice ; lay to four nights, 
owing to the density of the fog ; saw an iceberg two miles in 
length ; no ice seen on the Banks. 

Ship Virginia, Allen, latter part of January, 1844, was 34 hours 
fast in the ice. On the Banks, in a hurricane, lost foresail and 
main-topsail — saw large quantities of ice. 

Ship Swanton, Heath, from 18th to 21st July, 1842, experi- 
enced thick foggy weather, latitude 43° and longitude 49° to 
54°, passed upwards of 300 icebergs, some of them very large ; 
came near being wrecked on them, having run between two 
large islands in the night, which nearly rubbed the ship on each 
side before we discovered them, notwithstanding all hands were 
upon the lookout. 

Captain William Wier, bound eastward, gave the following ac- 
count. On the 9th of March, 1787, latitude 42° N., longitude 
55^ 40' W., was called by the mate to see a large ridge of 
breakers: altered my course from E. S. E. to S., the appearance 
of breakers being N. N. E., and trending from E. N. E. to W. S. 
W. March 11th, latitude 43° 34', found myself in the midst of 
a large body of ice, trending E. N. E. and W. S. W. ; soon got 
through. March 13th, latitude 44° 03', at 8 a. m., made a large 
body of ice, extending beyond view from mast-head, and trend- 
ing N. E. by E. and S. W. by W. At 10 p. m., met a larger 
body of ice, which entirely stopped the ship's way. On the morn- 



Drift Ice and Currents of the North Atlantic. 9 

ing of the 14th, found myself enclosed, and conld see no water 
from mast-head, except one small hole, into which 1 pressed the 
ship ; in 23 fathoms water on the Grand Bank. In this dismal 
situation lay with my sails hauled up, till 21st March, seeing no 
sea from main top-gallant-mast head. On the 17th went on the 
ice to take a view of an island of ice which bore from us W. S. 
W. We set out at 12 o'clock, and travelled one hour and thirty 
five minutes before we reached it. We found it aground in 25 
fathoms, the main body passing fast by it, setting S. E. two and 
a half miles an hour, as I judged. On our return, having been 
absent three hours, the ice island bore W. N. W., having altered 
four points. 

On the first day of January, 1844, Captain Burroughs, in the 
ship Sully, met with an iceberg in the Atlantic, in latitude 45°, 
longitude 48°. This is earlier in the winter than any other case 
which we have met with. Captain B. states that he had met 
with ice near this position on the first of February, on a former 
voyage. 

In September, 1822, Captain Couthouy saw an iceberg aground 
on the eastern edge of the Grand Bank, in latitude 43° 18^, lon- 
gitude 48° 30'. Sounding three miles inside of it, the depth was 
found to be 105 fathoms. In the month of August, 1827, the 
same observer, while crossing the Banks in latitude 46° 30', lon- 
gitude 48° W., passed within less than a mile of a large iceberg 
which was stranded in between 80 and 90 fathoms water. He 
was so near as to perceive, distinctly, large fragments of rock and 
quantities of earthy matter imbedded in the sides of the iceberg, 
and to see, from the fore yards, that the water for at least a quarter 
of a mile round it was full of mud, stirred up from the bottom by 
the violent rolling and crushing of the mass. 

On the 27th of April, 1829, Captain Couthouy passed, in lati- 
tude 36° 10' N., longitude 39° W., [probably south of the Gulf 
Stream,] an iceberg, estimated to be a quarter of a mile long, and 
from SO to 100 feet high. It was much wasted in its upper por- 
tion, which was worn and broken into the most fanciful shapes. 
In 1831, at daylight of the 17th of August, latitude 36° 20' N., 
longitude 67° 45' W,, upon the southern edge of the Gulf Stream, 
he fell in with several small icebergs, in such proximity to each 
other as to leave little doubt of their being fragments of a large 
one, which, weakened by the high temperature of the surround- 



10 Drift Ice and Currents of the North Atlantic. 

ing water, had fallen asunder during a strong gale which had 
prevailed from the southeast.* 

Ship St. James, Meyer, July 12, 1844, latitude 44°, longitude 
47° 12', passed 12 large icebergs ; July 20, passed 25 do. ; and 
July 21, passed 30 do; latitude 43° 50', longitude 52° 26', saw 
the last of it. 

John L. Hayes, Esq., in the Boston Journal of Natural His- 
tory, states that Capt. Crocker, of New Bedford, measured with 
his sextant an iceberg which was aground on the Bank of New- 
foundland, and found it to be half a mile long and two hundred 
and forty four feet high. Also, that Capt. Matthew Luce, of New 
Bedford, saw an ice-island of one hundred feet in height, aground 
in forty eight fathoms, on the Bank, and that the fishing vessels 
had sailed around it for thirty days. 

Ship Switzerland, Knight, May 5th, 1844, in latitude 47° N., 
longitude 46° W., at 5 a. m. met with a perfectly solid field of 
ice, and the wind being N. E. hauled out to S. E. After coast- 
ing the ice forty miles, found it turned to E., and that the ship 
was embayed. Tacked to N., and after four tacks of one hour 
each, the wind hauled to S. W. ; steered east a short distance 
from the ice. Afterwards turned to the south, and the wind 
hauling to the westward, steered S. S. W. for forty miles more, 
when the ice became broken, and very soon was entirely, clear 
of it, having sailed eighty miles along an unbroken coast of ice, 
exactly in appearance like low land covered with snow. The 
wind continuing to the westward, saw more or less ice for three 
following days, but none south of latitude 44° 43', nor west of 
longitude 49°. 

Ship Formosa, Crawford, June 18th, 1842, latitude 38° 40', 
longitude 47° 20', saw an iceberg 100 feet high and 170 feet 
long. 

On the passage out in the Acadia, on the 16th of May, in lat- 
itude 46°, longitude 47°, there were seen about 100 icebergs, 
some of them of large size, and one from 400 to 500 feet high, 
bearing so strong a resemblance to St. Paul's, that it was at once 
christened after that celebrated cathedral. The dome was per- 
fect, and it required no extraordinary stretch of imagination to 

supply the turrets, pinnacles, and other parts of the building. 

% 

* See this Journal, Vol. xLiii, 1842. 



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Drift Ice and Currents of the North Atlantic. 11 

On the homeward passage of the Acadia, on the 6th of June, the 
same object was seen, and the immediate exclamation on board 
was, " There's our old friend, St. Paul's." In the interim be- 
tween the two views, the iceberg had drifted about seventy 
miles.* 

An immense ice-island was seen on the 10th July, 1841, in lat- 
itude 43° 54', longitude 58° 12', by Captain ^Ricker, of the 
Apollo, at Boston. He reports that his thermometer fell when 
near it forty degrees. 

It may be proper to state here, that many ice observations have 
been placed on the chart without a reference to the date or the 
vessel which reported them, and the want of room for the refer- 
ences has rendered this in a degree unavoidable. In compiling 
the chart, one hundred and fifty seven separate reports have been 
consulted, the general character of which may be estimated by 
the foregoing examples. Many other accounts might have been 
obtained, but it is believed that these are sufficient for an approx- 
imate estimate of the course and positions of the ice in various 
seasons, so far as relates to the routes of vessels coming from Eu- 
ropean ports. 

On the Westerly tendencies of the Polar Ice-currents, and their 
Influence on the Gulf Stream. 

In further noticing the westerly and southerly progress of the 
cold currents from the arctic regions, we avail ourselves of the 
researches of Rennell, who states that " a current from Green- 
land and the Arctic Sea joins the Gulf Stream on the east of the 
Grand Bank of Newfoundland, somewhere about latitude 44°, 
and between the meridians of 44° and 47°." In the month of 
May its direction has been found to be between S. W. by S. and 
S., and its temperature [apart from the ice] 43° to 47° of Fah- 
renheit. The temperature taken not far to the eastward of it 
was 62° to 63°, and an easterly current of 30 miles [per day] 
of the same water (i. e. gulf water,) was found at a distance from 
the eastern edge of the S. W. by S. cold stream. This is, doubt- 
less, the current that brings down the ice from Greenland, &c., 
to the east of the bank of Newfoundland, and ice has been seen 
in the line of this very current, by different persons in different 

* English paper. 

2 



12 Drift Ice and Currents of the North Atlantic. 

years. The navigators to Newfoundland and New England 
place the junction of these currents in about latitude 41°, lon- 
gitude 49°, which shows how erroneous their ideas are on this 
subject." 

Rennell likewise states that " there is also a smaller [?] current 
that passes down the coast of Labrador, and eastern side of New- 
foundland, and carries ice in sight of the coast." He also says, 
that " it appears both from his own and other people's observa- 
tion, that two distinct streams of ice exist ; one on the east of 
the Bank, the other ranging along the coasts of Labrador and 
Newfoundland ; and then obliquely across the Bank in a S. by 
E. direction ; whilst that from Greenland, &c., runs between S. 
by W. and S. S. W. This last current appears to fall into the 
Gulf Stream about the latitude of 43° or 44° ; and between the 
meridians of 45° and 50° W. The ice is, of course, carried into 
the Gulf Stream, where, from the warmth of its temperature, it 
must rapidly dissolve."* Rennell also states that many ice islands 
are found to the westward of the above, " in the line of the route 
from Halifax," and that they are often seen in the Strait of Belle 
Isle." We quote also the following : 

" An experienced commander, long in the Newfoundland trade, 
has said that the branch current which appears to come from 
Hudson's Bay, always sets to the south-westward (perhaps S. S. 
W.,) off the eastern coast of Newfoundland: sometimes at the 
rate of two miles an hour ; its strength, however, varying with 
the direction and force of the wind. Passing down the eastern 
coast of Newfoundland, it turns about Cape Race, and sets thence 
along the south side of the island, until it meets with the current 
from the St. Lawrence, [through the Strait of Belle Isle,] a little 
to the westward of St. Pierre and Miquelon Islands. 



* I have not sufficient knowledge of that portion of the Greenland current 
which lies north of the Banks, to enable me to determine if its course from the 
coast of Greenland be directly towards the Flemish Cap and the eastern side of 
the Grand Bank, or whether it may not fall in with the Labrador current in lon- 
gitude 48° to 51° off the Strait of Belle Isle, or the southern coast of Labrador, run- 
ning from thence southeasterly parallel to the coast of Newfoundland and outside 
of the Labrador current, carrying with it the belt or stream of ice which it brings 
from the Greenland seas. It is hoped that this point may be satisfactorily deter- 
mined, and in the mean while I have ventured to indicate on the ice-chart, hypo- 
thetically, the more direct route to the eastern ice region, as being that of the Green- 
land current. W. C. R. 



Drift Ice and Currents of the North Atlantic. 13 

" When the Virgin Rocks, lying about 80 miles W. by S. from ^ )( ^ 
Cape Race, were surveyed in July, 1829, the current ^et over 
them to the W. S. W. at the rate of one mile an hour. 

"It is probable that this westerly current impinges on the 
easterly one, and continues its course, with diminishing velocity, 
towards Breton Island, where it blends with that branch of the 
St. Lawrence stream which sets to the S. W. between Sable Isl- 
and and Nova Scotia. 

" The sea between the Grand Bank of Newfoundland and the 
Banks of Nova Scotia is distinguished by its drifts of cold water, 
varying with the wind and seasons."* 

In further proof of the westwardly pressure of the polar current 
upon the American coast, we may state, on the authority of 
Captain Bayfield, the able officer who surveyed the Gulf and 
River of St. Lawrence, that " in spring the entrance and east- 
ern parts of the Gulf are frequently covered with ice, and ves- 
sels are sometimes beset for many days ;" and that " the reality 
of a current inwards through the Strait of Belle Isle, is con- 
firmed by the presence of icebergs, which it transports into the 
Gulf in summer, against the prevailing S. W. winds, frequently 
carrying them as far as Mecatina, and sometimes even to the 
neighborhood of the east point of Anticosti." This last position 
is nearly 300 miles from the entrance of the strait, and almost 
half way to Quebec. 

But even stronger proof of this inward pressure of the cold 
current into the gulf and estuary of St. Lawrence is found in the 
icy temperature of its deeper waters during the summer. Thus, 
in the middle of the estuary, ofi" Matan, and more than 200 miles 
above the east point of Anticosti, on the 8th of July, Dr. Kelly 
found the temperature of the surface water 60^, — at 30 fathoms 
35°, — at 50 fathoms 34°: the whole depth at that point being 
132 fathoms. A subsequent trial in this portion of the river 
showed the surface water at 57°, — at half a fathom depth 44°, — 
5 fathoms 40°,— 10 fathoms 38°,— 100 fathoms 35°. At Ta- 
dousac, about half way to Quebec from the place of the last ob- 
servation. Dr. Kelly found the temperature, in September, as low 
as 36°, after an easterly gale, which mingles the shallow stream 
of the surface with the deeper waters. Numerous other obser- 

* Purely, in Rennell. 



14 Drift Ice and Currents of the North Atlantic. 

vations made at different times and places, during the survey, 
confirmed these results. Hence it appears that the drainage 
waters received by the rivers were discharged by means of the 
surface current, which swept over the cold subjacent waters that 
were brought in by the polar current and the flood tide. These 
facts should be remembered in viewing the relations of the polar 
currents to the Gulf Stream. 

In relation to the southern outlet of the Gulf of St. Lawrence, 
it has been common for navigators and others greatly to overrate 
the proper river current of the St. Lawrence, in its extension 
southward of Breton Island and Nova Scotia. This fresh-water 
current, when compared with the branch of the polar current 
which joins it through the Strait of Belle Isle, is but of insignifi- 
cant volume ; and the current through this strait, in its turn, is 
but an ocean rill, when compared with the great volume and 
force of the cold currents which pass to the eastward and south- 
ward of Newfoundland. 

It appears that Rennell was embarrassed in his investigation 
of the polar currents of this region, by admitting the assumption 
that a portion of the cold water, eastward of Newfoundland, was 
caused by the Bank itself. This hypothesis had been sanctioned 
by distinguished writers, but the observations and facts on which 
it was founded can now be satisfactorily explained by the admit- 
ted influence of cold currents, either superficial or sub-aqueous. 
He appears, also, to have viewed the Gulf Stream as opposing a 
direct obstacle to the further passage of the polar currents, but it 
appears to us, that the streams of existing aqueous currents are 
found intersecting each other, much in the same manner as they 
would pass through quiet waters, and that they quietly impose or 
imbed upon each other like as stratified currents of air, or lateral 
currents from the forks of rivers, are found to accommodate each 
other, in their respective courses. In these river cases, as apart 
from the extraneous deflection by the shores, while the original 
momentum of each stream continues, one of these may be borne 
away from its original course, and thus be resolved to a new or 
modified direction by the further progress of the current in which 
it is imbedded; but in such cases, a diversion of the course of 
the lower current does not usually take place. 

In the case of ocean ice-currents which intersect a surface 
cross current, while the common surface ice conforms more or 



Drift Ice and Currents of the North Atlantic. 15 

less nearly to the new direction of the current on which it floats, 
the deeply immersed ice masses, having probably their greatest 
bulk immersed in the lower or deeper current, are thus resolved, 
by a real conflict of impelling forces, into a still difl'erent course, 
which conforms more or less nearly to that of the lower or sub- 
aqueous stream, according to the respective areas exposed to the 
action of the two currents, and their respective velocities. The 
geographical course of the body of the Gulf Stream, according to 
our best information, commonly touches the southern point of the 
Grand Bank in latitude 43° N., but the overflow or outspreading 
portion of the Stream often sweeps over the southern part of the 
Bank, as a surface current, when unimpeded by the ice. When 
the ice appears in great quantities it is probable that the Gulf 
Stream current coming from the west, carries the ice more east- 
wardly, from its previous southwesterly course. In thus yielding 
to the joint influence of the two currents, the surface ice assumes a 
new direction, towards the south or southeast. 

Grounded icebergs, when quite stationary, afford the best means 
for observing the course of the common ice fields. The course 
of the ice-drift, within the influence of the Gulf Stream, doubtless 
varies at difljerent times and localities, and must be greatly influ- 
enced by the depth of the floating masses. For in the case of 
icebergs or islands, particularly those which come down from the 
Greenland seas and pass eastward of the Grand Bank, their great 
depth subjects them to the continued impulsion of the lower or 
arctic current after they arrive within the influence of the Gulf 
Stream, the main part of the cold current passing beneath the 
warmer one, by means of its deeper position as well as greater 
specific gravity. 

This may be shown from the cases before recited, of immense 
icebergs which have been impelled into the body of the Gulf 
Stream, where, instead of being drifted off" to the eastward, in con- 
formity with its course and with the like tendency of the pre- 
vailing winds, some of these floating islands have been forced 
across the body of the stream, and in some cases even far beyond 
its ordinary limits, to a latitude lower than that of the southern 
boundary of Virginia ; as shown in the two cases given by Capt. 
Couthouy. The most eastward of these, in longitude 39°, and 
south from the usual eastern limit of the Greenland icebergs that 
arrive in the latitude of the Banks, was near seven degrees lower 



16 Drift Ice and Currents of the North Atlantic. 

in latitude than the southern extremity of the Grand Bank. The 
other icebergs noticed by him, in like latitude, and longitude 
67° 35', probably passed near to Newfoundland, and their position 
shows, in a more striking manner, the strong westwardly ten- 
dency of the polar current. 

No impulsion but that of a vast current, setting in a general 
southwesterly direction and passing beneath the Gulf Stream, 
could have carried these immense bodies to their observed posi- 
tions, on routes which cross the gulf current in a region where 
its average breadth has been found to be about two hundred and 
fifty miles. 

The continued southwestern, and even more westwardly course 
of that portion of the polar current which is found southward of 
Newfoundland and Nova Scotia and west of the Gulf Stream, is 
conclusively shown by the two icebergs met with by H. M. packet 
Express, July 7, 1836, on the southern edge of the Sable Bank, 
about seventy-five miles southwest from Sable Island. The 
highest of these, estimated at 180 feet, was in latitude 43° 14', 
longitude 61° 17', the other, 150 feet high, in latitude 43° 09', 
longitude 61° 26'. Owing to the great depth of these ice islands, 
they could not have passed through the Strait of Belle Isle, but 
must have been carried by the main current eastward and south- 
ward of Newfoundland to their observed position, which, by the 
nearest course, is near 500 English miles from ofi" Cape Race, the 
southeast point of that island, in the direction S. 63° W., true 
meridian, or W. S. W. J S. Of the further extension of this 
portion of the polar current, in diminished force, along the coast 
of the United States and the western border of the Gulf Stream, 
as far as Cape Hatteras, if not to Florida, we have formerly 
spoken, in another place.* 

The finding of a low temperature on the southern part of the 
Grand Bank, or even to the southward of latitude 43°, is not suf- 
ficient evidence of the entire absence of the Gulf Stream current : 
for the recent presence or proximity of floating ice must neces- 
sarily cause a great reduction in the surface temperature, and 
there is no natural process by which the cold water of the sur- 
face stream can be changed for warmer with a rapidity sufficient 
to preserve a temperature at all corresponding to the warm por- 
tions of the Gulf Stream. 

* This Journal, Vol. xxxii, p. 349. 



Drift Ice and Currents of the North Atlantic. 1 7 

It is well known that vessels in the northern part of the Gulf 
Stream, while steering parallel to its general course, have met 
with successive and striking changes in the temperature of the 
water and sometimes with ice, to the southward of Nova Scotia 
and Newfoundland, and in the proper line of the polar current. 
This is well shown in the journals of the ships Eliza and Grand 
Turk, as published in some former editions of the Coast Pilot. 
In latitude 41° 53', longitude 56° 52', the Eliza found the water 
at the depth of 70 fathoms two degrees warmer than that at the 
surface, the temperature of the latter being 40°, and an ice island 
bearing S. S. E., distant seven miles. S. S. W. and S. of the 
Grand Bank, and in nearly the above latitude, the Eliza again 
met with cold water and passed several ice islands. Rennell has 
also recognized these cold veins or bodies of water in the Gulf 
Stream. It appears, therefore, that in this portion of the Gulf 
Stream, neither its presence nor its actual limits can be determined 
with certainty by the thermometer, during the ice season. 

It appears in the pages of the Coast Pilot, that Capt. Billings, 
in June, 1791, found the temperature of the water in the Gulf 
Stream to have fallen ten degrees, in latitude 39°, southward of 
the Bank, and that the like had been observed by Dr. Franklin 
and Col. Williams, in the same region. But, judging from the 
latitude, it is not improbable that these observations were made 
to the southward of the true border of the Gulf Stream. If this 
be the true solution, it is indicative of the partial re-appearance of 
the polar current, after passing beneath the Gulf Stream ; and 
there is evidence of its further course to the S. W. and W. S. W., 
near the border of the Stream. 

This leads us to notice a probable, if not a principal cause of 
the great variations, which have been reported, in the position 
and limits of the Gulf Stream, in its eastward progress. Rennell, 
we conceive, rightly supposes an overfloio or outspreading of the 
Gulf Stream upon the ocean waters, as it proceeds in its course. 
Now we know, from well established cases, that overflowing 
streams, upon denser waters, are often very shallow ; and Capt. 
Bayfield has shown, in the case of the estuary and Gulf of St. 
Lawrence, that the effect of a storm is to break up, for the time, 
this superficial current and amalgamate it with the deeper and 
colder waters. Hence we may infer, that in good weather and 
a smooth sea, the thermometric breadth of the Gulf Stream may 



18 Drift Ice and Currents of the North Atlantic. 

be far greater than in rough weather ; and that it is most straitened 
in its limits immediately after the occurrence of a great storm. 

Perhaps too little consideration has hitherto been given to the 
character and eifects of the polar currents. These appear to be 
well worthy of the attention of both the navigator and the phi- 
losopher. We have seen that the moderate but miceasing flow 
of these currents often interposes an icy barrier in one of the most 
common routes of navigation. The observing geologist will also 
discern in the courses of the ice-currents of the Atlantic, both 
before and after their contact with the tropical stream, a striking 
coincidence with the directions of the two systems of strife which 
mark the abraded surfaces of the continental rocks ; the origin of 
which must be referred to the early and prolonged period when 
these rocks were situated beneath the ceaseless flow of the ocean 
currents.* 

New York, December 30th, 1844. 

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